select * from tb_student
select * from tb_inf_student
select * from tb_bibliography
select * from tb_book
select * from tb_record
--使用STUDENTS数据库

--1.创建tb_student(name)索引  填充因子设为50

select * from tb_student
create nonclustered index IX_Score on tb_student(name)
with (
 fillfactor=50
)
 
--2.创建tb_record(borrow_time,return_time) 使用索引查询没还书的同学并且让没还书的同学将图书归还

create index IX_time on tb_record(borrow_time,return_time) 
select borrow_time, return_time from tb_record with (index=IX_time)  where return_time is null
--3.增加新列id() 创建聚集索引tb_book(id)
alter table tb_book add id nvarchar(50);
go
create index IX_id on tb_book(id);